Exoplanet Discoveries and Updates

[The Astronomer]

There were additional discoveries in a young solar analog known as V1298 Tauri, making the total planet count for this system four.

V1298 Tauri c
Semi-major axis: 0.0825 AU
Orbital period: 8.24958 days
Eccentricity: <0.43
Radius: 5.59 Earths
Discovery announcement: 10 Oct 2019

V1298 Tauri d
Semi-major axis: 0.1083 AU
Orbital period: 12.4032 days
Eccentricity: <0.21
Radius: 6.41 Earths
Discovery announcement: 10 Oct 2019

V1298 Tauri b
Semi-major axis: 0.1688 AU
Orbital period: 24.1396 days
Eccentricity: <0.29
Radius: 10.27 Earths
Discovery announcement: 26 Feb 2019

V1298 Tauri e
Semi-major axis: 0.308 AU
Orbital period: 60 days
Eccentricity: <0.57
Radius: 8.74 Earths
Discovery announcement: 10 Oct 2019

Although individual masses are unknown, simple dynamic arguments suggest total masses of <28 Earth masses and <120 Earth masses for the c-d and d-b planet pairs, respectively. The densities of these planets appear to be way lower than their mature counterparts, suggesting that they're still in the process of radiatively cooling and contracting.